Centrifugal fan and housing thereof

ABSTRACT

A centrifugal fan includes a casing and a fan cover located on the casing. The casing includes a sidewall defining at least one latching groove. A step is formed in the at least one latching groove. The fan cover includes at least one latching leg corresponding to the at least one latching groove. The at least one latching leg includes a locking portion. The locking portion includes a plurality of wedge-shaped hooks extending latarally and outwardly from the locking portion. The hook has a tapered outer surface for guiding the at least one latching leg to slide into the at least one latching groove and a locking shoulder formed at a topmost portion of the hook. The locking shoulder of the at least one latching leg abuts against the step of the at least one latching groove.

BACKGROUND

1. Technical Field

The disclosure relates to a centrifugal fan, and more particularly to a centrifugal fan which can be conveniently assembled.

2. Description of Related Art

Centrifugal fans are generally used to dissipate heat from heat sources in the art. A typical centrifugal fan includes a housing and an impeller rotatablely received in the housing. The housing includes a casing and a fan cover fixed on the casing. In the art, the fan cover is fixed on the casing typically via a plurality of screws. However, such assembly process of the housing is complicated and time-consuming.

For the foregoing reasons, therefore, there is a need in the art for a centrifugal fan which can overcome the limitations.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is an assembled, isometric view of a centrifugal fan according to an exemplary embodiment.

FIG. 2 is an exploded, isometric view of the centrifugal fan of FIG. 1.

FIG. 3 is an enlarged view of a circled portion III of FIG. 2.

FIG. 4 is an enlarged view of a circled portion of FIG. 2.

FIG. 5 is an enlarged view of a circled portion V of FIG. 1.

FIG. 6 is a cross-sectional view of the centrifugal fan of FIG. 5, taken along line VI-VI thereof.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a centrifugal fan 1 includes a housing 3 and an impeller 2 rotatably mounted in the housing 3. The housing 3 includes a casing 5 and a fan cover 4 located on the casing 5. The casing 5 and the fan cover 4 cooperatively define a receiving space 6 in the housing 3 and the impeller 2 is received in the receiving space 6.

The fan cover 4 includes a top plate 40 and a plurality of latching legs 8. The top plate 40 defines an air inlet 41 in a center portion thereof. Three cutouts 42 are defined in an outer peripheral edge of the top plate 40. Referring to FIG. 3, each of the latching legs 8 extends perpendicularly and downwardly from an edge 421 of a corresponding cutout 42. The latching leg 8 includes an outwardly curved head portion 81 connected with the top plate 40, a neck portion 82 extending downwardly from a bottom end of the head portion 81 and a locking portion 83 at a bottom end of the neck portion 82.

The locking portion 83 includes two opposite wedge-shaped hooks 831, which extend laterally and outwardly from the locking portion 83. The hook 831 has a tapered outer surface 834 and a locking shoulder 833 formed at a topmost portion of the hook 831. A slot 832 is longitudinally defined through the locking portion 83 and the neck portion 82, thereby providing resiliency to the locking portion 83 in a transverse direction thereof.

The casing 5 includes a base plate 51 and a sidewall 52 extending upwardly and perpendicularly from an outer peripheral edge of the base plate 51. The sidewall 52 defines a first air outlet 53 and a second air outlet 54 adjacent to the first air outlet 53. The first air outlet 53 and the second air outlet 54 are separated from each other by a separating plate 55 perpendicular to the base plate 51.

Referring also to FIGS. 4-6, the sidewall 52 defines a plurality of latching grooves 56 in an outer peripheral surface 521 thereof corresponding to the latching legs 8 of the fan cover 4, respectively. The latching groove 56 includes an upper narrow portion 561 and a lower wide portion 562 located under the narrow portion 561. The narrow portion 561 has a smaller width than the wide portion 562. A first step 563 is formed at a joint between the narrow portion 561 and the wide portion 562.

The sidewall 52 defines a cutout 713 in a top thereof corresponding to and communicating with the latching groove 56. The cutout 713 has a larger width than the narrow portion 561 of the latching groove 56, with a second step 714 being formed at a joint between the cutout 713 and the narrow portion 561.

The sidewall 52 forms a clamping portion 7 on the outer peripheral surface 521 thereof corresponding to the narrow portion 561 of the latching groove 56. The clamping portion 7 includes two opposite L-shaped clamping arms 71 spaced from each other thereby providing resiliency to the clamping portion 7 in a transverse direction thereof. The two clamping arms 71 are respectively located at two opposite sides of the narrow portion 561 of the latching groove 56 and surround the narrow portion 561 of the latching groove 56.

In assembly, the fan cover 4 is firstly placed on the top of the casing 5 with each of the latching legs 8 aligned with a corresponding latching groove 56. The top plate 40 of the fan cover 4 is then pushed downwardly to cause the latching leg 8 to move downwardly. The tapered outer surface 834 of the hook 831 guides the latching leg 8 to slide into the latching groove 56. Thus, the hooks 831 of the locking portion 83 enter into the latching groove 56, and the tapered outer surfaces 834 are brought into interaction with an inner surface of the narrow portion 561 to cause the hooks 831 to contract inwardly toward each other. Once the hooks 831 have passed through the narrow portion 561 of the latching groove 56, the hooks 831 elastically restore back to their original state. The locking shoulders 833 of the locking portion 83 abut against the first step 563 of the latching groove 56, and the clamping portion 7 prevents the latching leg 8 from moving radially and outwardly in the latching groove 56. Since the neck portion 82 of the latching leg 8 has a smaller width than the narrow portion 561 of the latching groove 56, the neck portion 82 is received in the narrow portion 561. At the same time, the head portion 81 of the latching leg 8 is received in the cutout 713 and a bottom of the head portion 81 rests on the second step 714 of the cutout 713. Therefore, the fan cover 4 is easily and firmly fixed on the top of the casing 5.

It will be obvious that, within the scope of the invention, many variations are possible to those skilled in the art. The scope of protection of the invention is not limited to the example given herein. 

1. A centrifugal fan comprising: a casing comprising a base plate and a sidewall extending upwardly from an outer peripheral edge of the base plate, the sidewall defining at least one latching groove, the at least one latching groove having an upper narrow portion and a lower wide portion, the narrow portion being located above the wide portion, the narrow portion having a smaller width than the wide portion, a step being formed at a joint between the narrow portion and the wide portion; a fan cover located on the casing and comprising a top plate and at least one latching leg corresponding to the at least one latching groove, the at least one latching leg extending downwardly from an outer peripheral edge of the top plate and comprising: a head portion connected with the top plate; a neck portion extending downwardly from the head portion, the neck portion having a smaller width than the narrow portion of the at least one latching groove and received in the narrow portion of the at least one latching groove; and a locking portion formed at a bottom of the neck portion, the locking portion comprising a plurality of wedge-shaped hooks extending laterally outwardly from the locking portion, each of the hooks having a tapered outer surface for guiding the at least one latching leg into the at least one latching groove, a locking shoulder being formed at a top of each of the hooks, a slot being longitudinally defined through the locking portion and the neck portion, the locking shoulder of the at least one latching leg abutting against the step of the at least one latching groove; and an impeller rotatably mounted in a receiving space cooperatively defined by the fan cover and the casing.
 2. The centrifugal fan as claimed in claim 1, wherein the sidewall forms at least one clamping portion corresponding to the at least one latching groove, and the at least one clamping portion is configured for preventing the at least one latching leg from moving outwardly and radially in the at least one latching groove.
 3. The centrifugal fan as claimed in claim 2, wherein the at least one clamping portion comprises two opposite L-shaped clamping arms spaced from each other, the two clamping arms being respectively located at two opposite sides of the narrow portion of the at least one latching groove and surrounding the narrow portion of the at least one latching groove.
 4. The centrifugal fan as claimed in claim 1, wherein the sidewall defines a cutout in a top thereof corresponding to and communicating with the at least one latching groove, the cutout having a width larger than that of the narrow portion, with a step being formed at a joint between the cutout and the narrow portion.
 5. The centrifugal fan as claimed in claim 4, wherein the head portion of the at least one latching leg is received in the cutout, a bottom of the head portion resting on the step formed at the joint between the cutout and the narrow portion.
 6. A housing of a centrifugal fan comprising: a casing comprising a base plate and a sidewall extending upwardly from an outer peripheral edge of the base plate, an outer surface of the sidewall defining at least one latching groove, a step being formed in the at least one latching groove; a fan cover located on the casing and comprising at least one latching leg corresponding to the at least one latching groove, an elastically deformable locking portion being formed at a bottom of the at least one latching leg, the at least one latching leg being received in the at least one latching groove and the locking portion abutting against the step of the at least one latching groove.
 7. The housing as claimed in claim 6, wherein the locking portion comprises two opposite wedge-shaped hooks, the hook has a tapered outer surface and a locking shoulder formed at a topmost portion thereof, a slot is longitudinally defined between the two hooks and provides an elastically deformable space for the locking portion, and the locking shoulder abuts against the step of the at least one latching groove.
 8. The housing as claimed in claim 6, wherein the sidewall forms at least one clamping portion corresponding to the at least one latching groove, and the at least one clamping portion is configured for preventing the at least one latching leg from moving outwardly and radially away in the at least one latching groove.
 9. The housing as claimed in claim 8, wherein the at least one clamping portion comprises two opposite L-shaped clamping arms spaced from each other, the two clamping arms being respectively located at two opposite sides of the narrow portion of the at least one latching groove and surrounding the narrow portion of the at least one latching groove.
 10. The housing as claimed in claim 6, wherein the sidewall defines a cutout in a top thereof corresponding to and communicating with the at least one latching groove, the cutout having a larger width than the narrow portion, with a step being formed at a joint between the cutout and the narrow portion.
 11. The housing as claimed in claim 10, wherein the head portion of the at least one latching leg is received in the cutout, a bottom of the head portion resting on the step of the cutout. 